This is - virtually - a meaningless question.
As far as websites go, all CF does is accept a request from a web server and generate character(*) data by way of a response which it passes back to the web server, which sends it the requesting client agent, which is usually a web browser, possibly IE8.
So provided the character data CF generates is well-formed mark-up that IE8 can render, there is no problem. But that's all down to the (developer-written) code written in the CFML templates, it's nothing intrinsically to do with CF (any version).
(*) It occurs to me that CF can also generate binary data - eg: images - but for the sake of this reply, that's not relevant.